Polycarbonates are tough, rigid engineering thermoplastics. They are melt processable and can easily be formed into optical and ophthalmic products by injection molding, instead of more time consuming and expensive casting processes. There is increasing demand for high refractive index materials for optical and opthalmic products. Polycarbonates, however, have only a limited refractive index.
Thus, there is a need for melt processable materials which have high refractive indices.